While facial oils have a variety of causes, diet is believed to be one of the leading contributors. Many people make drastic changes to their diet in order to control their acne, and this has led to many different beliefs about what may lead to excess skin oil.

One of the leading beliefs is that sodium causes acne.

Sodium - or more specifically, salt – is found in many different foots. The belief is that excess sodium leads to an increase in facial oils, which ultimately allows acne causing bacteria to grow.

Currently there is little to no evidence that sodium (excess or otherwise) causes acne in any way.

That is not to say that studies haven't hinted a link may exist, only that the relationship isn't strong enough to be a concern, and may simply be noise within the data.

For example, a study in 1965 put 30 acne patients on a low sodium diet for 3 months. Of those 30 patients, only four appeared to show any decrease in acne lesions. The remaining 26 experienced no changes in their overall acne.

One could look at this study and say that reducing salt intake helped four people reduce their acne, but the reality is that in any given 30 day sample a reduction in acne is likely for some patients. The likelihood is that there was simply no effect of the reduce sodium intake.

Several population based studies have looked at sodium and acne as well. Most have found that those in areas with high sodium intake do not appear to have any increase in acne compared to those with a low sodium intake.

It should be noted that these studies were not well controlled. In fact, the authors of a summary paper on nutrition and acne state:

"Until 2005, cross-sectional, case–control, cohort, and clinical intervention studies designed to address the relationship between diet and acne typically failed to incorporate adequate controls, objective measures, and appropriate statistical analyses. Well-designed prospective studies published since 2005 have elucidated the mechanisms whereby particular foods and dietary constituents may influence acne risk and severity. In order to test the efficacy of dietary interventions, prospective, randomized trials, including controls for environmental stressors, acne medications, age, pubertal stage, and age at menarche, are essential."

In other words, no studies appear to have had an adequate control group or shared their reporting methods, so it is impossible to say with certainty whether nearly any type of food group contributes to oily skin. So the answer to "does excess sodium cause acne" is neither a yes or a no. The truth is that most studies have been so woefully inadequate that the link between sodium and acne is still unclear.

However, the likelihood is that sodium does not cause acne.

Both anecdotally and in what little research has been completed, there does not appear to be any evidence that sodium causes acne, or that sodium contributes to acne in any way.

As established, the lack of adequate studies means that it is possible for there to be a yet-unknown link between sodium and acne.

However, there is unlikely, because sodium does not appear to play much of a role in skin oil. Some believe that it's possible that sodium leads to water retention (pulling liquids away from skin), which then causes the skin to overcompensate and create more oils. It's an interesting theory, but it doesn't have much support.

If sodium caused acne (and again, there is little reason to believe this is the case), it's possible that it has more of a secondary relationship to acne breakouts.

There are three potential causes of acne that may be linked to sodium.

Possible Secondary Relationship

One example is that research does support the idea that it is possible that high glycemic carbohydrates may contribute to skin oils or acne breakouts. It is believed that high glycemic foods and fat may affect your body's hormones, which in turn may contribute to an increase in acne breakouts. Coincidentally, there often is a great deal of sodium in high glycemic, high fat foods, which could be one of the reasons that people that "cut sodium" out of their diets may have less overall acne – it's possible that in order to cut sodium, they cut high glycemic and high fat foods instead, and simply attributed the results to a sodium reduction.

Similarly, unhealthy diets that are high in sodium or fat intake may also lead to ill health. Ill health may lead to stress, and stress is known to be a cause of excess skin oils and acne breakouts. Eating healthy does play a role in the amount of stress you experience in life, so while sodium itself doesn't necessarily cause stress, those with high sodium diets may be more prone to it.

A researcher at the University of Buffalo has also stated that iodine may be a potential cause of acne. He argued that feeding iodine to cows is one of the reasons that dairy products may lead to acne breakouts. Iodine is actually a common additive to modern salts, because men and women generally do not get enough iodine in their diets. If this is the case, then salt in some ways may be causing acne breakouts, yet it would not be the sodium causing acne, but rather the iodine additive.

In the latter case, however, most dermatologists and researchers do not believe that iodine causes acne either. Most studies have failed to show a relationship, and while a few studies in the early 1960's linked iodine to acne, these studies were not well controlled.

Many will point to the lack of available research and claim that sodium does not cause acne. Yet this may be premature. Very few well controlled studies have ever been created to definitively link sodium and acne, which means that while no studies have proven a relationship, no studies have disproven a relationship either.

Yet the likelihood is that there is no link between sodium and acne, or at least not enough of a link to matter. Excess sodium is not good for your health, but it is unlikely to be contributing to acne breakouts.